There's no gaurantee that it will happen, or that if it did happen it would be at the June 20 meeting, but the presses are being warmed up.

Top Fed officials have said that they would support new measures if they became convinced the U.S. wasn't making progress on bringing down unemployment. Recent disappointing employment reports have raised this possibility, but the data might be a temporary blip. Moreover, the Fed's options for more easing are sure to stir internal resistance at the central bank if they are considered.

Their options include doing nothing and continuing to assess the economic outlook—or more strongly signaling a willingness to act later if the outlook more clearly worsens. Fed policy makers could take a small precautionary measure, like extending for a short period its "Operation Twist" program—in which the Fed is selling short-term securities and using the proceeds to buy long-term securities. Or, policy makers could take bolder action such as launching another large round of bond purchases if they become convinced of a significant slowdown.

Bloomberg TV Meanwhile, Jefferies David Zervos gives his take on the key levels to watch for more Fed action:

As always, it will be hard to pinpoint exact tipping points for a move - but I suspect that if we see a combination of the DXY (dollar index) at 86/88, and the spoo (S&P) at 1200/1225, the Fed will jump into action. I do not think we need to talk about the PCE or the U-rate when it comes to the Fed - the real triggers are in liquid market prices. And, in particular, if these levels in the DXY and spoo are breached, any sensible forecasts for forward looking employment and inflation that enter into a Taylor rule will plummet - hence accommodation follows!! In fact, take a look at a DXY chart since early 2008 - the 88 level was a good indicator for QE1 and QE2.